Assuming you mean mechanical dura ace and regular 20 speed Red, I’d go with Red. I run Force and its really good shifting, its hard to describe, its kind of clunky but also smooth, put it this way, when its set up well, there is zero chance of ever being in doubt that it shifts. Double tap is much nicer to use and you can get through the cassette in two long seeps of the shifter. Its also about 200gs lighter if i remember correctly.

As for framesets, sticking with the aero theme, I had a good look at the Giant Propel today at the London tri show and it was stunning, the v-brakes wont be too all tastes however. Others to consider are the Cervelo S2 and the Argon 18, the Ridley Noah and the Specialised Venge.

If I had your Option I would go for Sram Red, I have just got a new frame and went for Ultegra although very nice part of me feels the Sram Force would of been better as I like the idea of double tap and also prefer the sleeker looks of Sram. I found Ultegra at a lower cost by buying the components individually.

Unless your used to a particular type of shifter all the top end stuff is good, you’d get used to and enjoy any of them, Campag Record gets my vote though.
As you mentioned the Aeroad I thought I’d give you my view. I’m not sure about mixed reviews The Bikeradar one seems to be the only one out there doing the rounds. It seems a bit confused to me. The frame is plenty stiff enough, maybe for those 1000+watt sprints a world class sprinter might want something more brutal. But real world its fine. Payback might be its amazingly comfortable, noticeably more than the cf ultimate it replaced. for long hard days in the saddle, its the pick of most of the pro’s who have a choice from the Canyon range.
This guy seemed to do all right on one.

I’ve got Sram on my cx bike & Shimano on my road bike.
As soon as I can afford it the Sram will either be on here for sale or in the bin & replaced with Shimano-even if I have to fit Sora! Sram is hateful stuff IMO, horrible to set up, rear mech’s love to seize up too.
IF & it’s a big IF! you get a good set, it’s a nice shifting action, but thats about all I can say, sorry.

I work as a mechanic & have done for the last nine years, working on road, mtb & cx bikes on a daily basis, Cytech level 3 qualified
I’ve raced dh, xc, cx & road for the last fourteen years.
I think I know how to set up a road bike’s gears 😉

Have you looked at Campag? It’s worth a look if you’re shopping. I’ve got it in my road and CX really nice stuff, I like the hoods. Shimano I find doesn’t suit me as well but is great shifting. I’ve not tried Red.

in my opinion based on years of working on both as a professional mechanic, Shimano manufacturing quality is another level of quality and prowess beyond SRAM.

which means long term durability is superior, and this is something I see every day on bikes going through my workshop, we work on alot of high end road bikes with Dura Ace and Ultegra of mech and electronic flavours, SRAM Red, Campag Super Record.

Dura-Ace warranty=3 years, SRAM warranty=2 years

what this means in real world is Dura Ace / Ultegra have the edge on durability of shifter mechanisms, rear mech / front mech and brake calipers, especially in our wet climate where degradation due to wet / road salt is common

Shimano’s cranks / chainrings and front shifting are unrivalled in terms of performance under load, and ease of fitment for regular maintenance.